/*
Copyright 2016 Kai Ryu <kai1103@gmail.com>

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include <stdbool.h>
#include "action.h"
#include "i2cmaster.h"
#include "expander.h"
#include "debug.h"

static uint8_t expander_status = 0;
static uint8_t expander_input = 0;

void expander_config(void);
uint8_t expander_write(uint8_t reg, uint8_t data);
uint8_t expander_read(uint8_t reg, uint8_t *data);

void expander_init(void)
{
    i2c_init();
    expander_scan();
}

void expander_scan(void)
{
    dprintf("expander status: %d ... ", expander_status);
    uint8_t ret = i2c_start(EXPANDER_ADDR | I2C_WRITE);
    if (ret == 0) {
        i2c_stop();
        if (expander_status == 0) {
            dprintf("attached\n");
            expander_status = 1;
            expander_config();
            clear_keyboard();
        }
    }
    else {
        if (expander_status == 1) {
            dprintf("detached\n");
            expander_status = 0;
            clear_keyboard();
        }
    }
    dprintf("%d\n", expander_status);
}

void expander_read_cols(void)
{
    expander_read(EXPANDER_REG_GPIOA, &expander_input);
}

uint8_t expander_get_col(uint8_t col)
{
    if (col > 4) {
        col++;
    }
    return expander_input & (1<<col) ? 1 : 0;
}

matrix_row_t expander_read_row(void)
{
    expander_read_cols();

    /* make cols */
    matrix_row_t cols = 0;
    for (uint8_t col = 0; col < MATRIX_COLS; col++) {
        if (expander_get_col(col)) {
            cols |= (1UL << col);
        }
    }

    return cols;
}

void expander_unselect_rows(void)
{
    expander_write(EXPANDER_REG_IODIRB, 0xFF);
}

void expander_select_row(uint8_t row)
{
    expander_write(EXPANDER_REG_IODIRB, ~(1<<(row+1)));
}

void expander_config(void)
{
    expander_write(EXPANDER_REG_IPOLA, 0xFF);
    expander_write(EXPANDER_REG_GPPUA, 0xFF);
    expander_write(EXPANDER_REG_IODIRB, 0xFF);
}

uint8_t expander_write(uint8_t reg, uint8_t data)
{
    if (expander_status == 0) {
        return 0;
    }
    uint8_t ret;
    ret = i2c_start(EXPANDER_ADDR | I2C_WRITE);
    if (ret) goto stop;
    ret = i2c_write(reg);
    if (ret) goto stop;
    ret = i2c_write(data);
stop:
    i2c_stop();
    return ret;
}

uint8_t expander_read(uint8_t reg, uint8_t *data)
{
    if (expander_status == 0) {
        return 0;
    }
    uint8_t ret;
    ret = i2c_start(EXPANDER_ADDR | I2C_WRITE);
    if (ret) goto stop;
    ret = i2c_write(reg);
    if (ret) goto stop;
    ret = i2c_rep_start(EXPANDER_ADDR | I2C_READ);
    if (ret) goto stop;
    *data = i2c_readNak();
stop:
    i2c_stop();
    return ret;
}